The invention relates to apparatus for cutting a row of capsules from a capsule strip and for fixing them on a transverse row of filled receptacles advancing stepwise through a receptacle-filling installation.
In installations for filling receptacles one by one, filled receptacles pass one after another through a closure station in which a capsule dispenser brings a capsule onto the receptacle for closing and the capsule is sealed to the rim of said receptacle by conventional means. As a general rule, such capsules are delivered in sachets and there arises a problem of storing and handling such sachets. However a more important problem lies with guaranteeing that the sachets and the capsules are sterile, particularly when the receptacles contain foodstuffs.
In installations that thermoform receptacles in a strip of thermoplastic-material, that fill the thermoformed receptacles, and that close the filled receptacles, it is conventional to apply a capsule strip against the strip of thermoplastic material after at least one row of receptacles has been filled, to seal the two strips together, e.g. by heat-sealing, via the rims of the filled receptacles, and then to cut through the entire thickness of both strips simultaneously so as to separate the receptacles from the strips from which they have been cut out, leaving a perforated scrap strip. In such installations, the strips advance stepwise and in each cycle at least one row of receptacles is made, rows of receptacles made during earlier cycles are filled, and the filled receptacles are sealed with the capsule strip in a subsequent cycle. Such installations are fitted with means for ensuring that the thermoplastic strip and the capsule strip are sterile, each strip being delivered from a reel.
If an installation of the above type is used for thermoforming, filling, and closing receptacles that are reentrant, i.e. receptacles in which the rim is smaller in diameter than the body, then the perforated scrap strip comprises a large amount both of thermoplastic material and of capsule strip material.
In order to avoid high levels of wastage in the capsule strip, it is tempting to use capsules that are delivered in sachets and are dispensed from a dispenser placed above each column of receptacles filled in the thermoforming and filling installation, as in installations for filling individual receptacles, in spite of all of the problems of guaranteeing sterilization as explained above.
The state of the art is illustrated by documents U.S. Pat. No. 3,509,682, U.S. Pat. No. 6,161,367, and U.S. Pat. No. 4,250,686. In all those documents, the spacing between the cutting means is equal to the spacing between the receptacles for closing in a row.
The object of the invention is to propose apparatus for cutting and fixing receptacles that makes it possible to save capsule strip material.
The apparatus of the invention is particularly adapted to an installation for thermoforming receptacles from a thermoplastic strip, for filling the thermoformed receptacles, and for closing the filled receptacles, in particular when the receptacles are reentrant, having rims of diameter smaller than the diameter of their bodies.
The apparatus of the invention is also applicable to closing individual receptacles placed in transverse rows that are advanced stepwise, particularly in an installation for thermoforming receptacles from precut shapes and for filling the thermoformed receptacles.
The invention thus provides apparatus comprising:
means for causing a capsule strip to advance stepwise over the path along which rows of receptacles advance;
cutting means for cutting out a row of capsules from said capsule strip, said cutting means being disposed parallel to the row of receptacles for closing and above said row;
transfer means for transferring a row of capsules from the station where said capsules are cut out to a station for placing capsules on the receptacles for closing in a row;
fixing means for fixing at least partially the capsules placed on the respective rims of said receptacles; and
control means for controlling said means for advancing the capsule strip stepwise, said means for cutting out capsules, said transfer means, and said fixing means so that they operate synchronously with the means for advancing said rows of filled receptacles.
According to the invention, in the apparatus the spacing of the cutting means is smaller than the spacing of the receptacles to be closed, and the transfer means co-operate with cam paths.
The fact that the capsules are taken from a capsule strip makes it easier to maintain capsule sterility.
In addition, the size of the advance step of the capsule strip is independent of the size of the advance step of the rows of receptacles, thus making it possible to reduce wastage in the longitudinal direction of the capsule strip.
In order to achieve further savings of material in the capsule strip, and according to an advantageous characteristic of the invention, the path along which the capsule strip advances is oblique relative to the cutting means for cutting out a row of capsules.
For example, the path along which the capsule strip advances is at an angle of about 60E relative to the cutting means.
Preferably, the size of the advance step of the capsule strip is substantially equal to the spacing of the cutting means.
The spacing of the cam paths in the zone situated facing the cutting station for cutting out the capsules is equal to the spacing of the cutting means, and the spacing of the cam paths in the zone situated facing the capsule-placing station is equal to the spacing of the receptacles to be closed.
In a preferred embodiment of the invention, the transfer means for transferring a row of capsules comprise:
at least one row of parallel holding tubes carried by a cylinder mounted to turn about a support shaft placed facing the cutting station for cutting out capsules and over the station for placing capsules, the free ends of said tubes being suitable for holding the capsules by suction;
means for causing said cylinder to turn stepwise between a position for taking hold of capsules in which the tubes of said row face the cutting means and a position for placing capsules in which said tubes face downwards and their free ends are in the vicinity of the receptacles to be closed; and
means for putting said tubes into communication with a vacuum source while they are holding capsules and transferring them from the cutting station for cutting out the capsules to the placing station, and for putting them into communication with exhaust while the capsules are being placed on the receptacles to be closed.
Preferably, the transfer means further comprise means for moving the support shaft towards the cutting means while the cylinder is in its position for taking hold of a row of capsules, and downwards while the cylinder is in its position for placing capsules so as to enable capsules to be put into position on the rims of the receptacles.
According to an advantageous characteristic, the cylinder has a plurality of rows of tubes disposed along generator lines that are regularly distributed angularly at the periphery of said cylinder and in such a manner that when a row of tubes is in its position for taking hold of capsules, another row of tubes is in its position for placing capsules, said cylinder turning stepwise in the same direction during each cycle.
Preferably, the position for taking hold of capsules is diametrically opposite the position for placing them about the support shaft of the cylinder.
According to another advantageous characteristic, the tubes in a row are slidably mounted independently of one another along respective guide shafts secured to the cylinder and parallel to the support shaft, each tube having a shoe guided by a cam path that is fixed relative to the support shaft of the cylinder.
Preferably, the means for at least partially fixing the capsules that have been placed on the respective rims of the row of receptacles to be closed comprise a set of arms that are substantially parallel to the advance direction of the rows of receptacles to be closed and carried by a shaft disposed above the path along which said rows of receptacles advance, the free ends of intermediate arms in said set of arms being disposed between the receptacles to be closed and the free ends of the extreme arms being disposed outside the extreme receptacles to be closed, said shaft being suitable for pivoting between a high position in which said arms release a passage for the transfer means while transferring a row of capsules, and a low position in which the ends of the arms bear against the side edges of the capsules placed on the rims of the receptacles to be closed, said ends of the arms including means for fixing spots of said capsules to the rims of the corresponding receptacles in co-operation with backing tools disposed beneath the side rims of the receptacles to be closed. Most advantageously, the backing tools are stationary.